1. Field of the Invention
The present invention relates, in general, to object locating systems and, more specifically, to systems for locating vehicles and other mobile objects from a central location utilizing global positioning signals.
2. Description of the Art
Global positioning systems (GPS) are used to obtain position information of an object anywhere in the world. A GPS receiver receives data signals from multiple GPS or GLONASS satellites and triangulates the data signals to obtain the measured position or location of the receiver. Such GPS receivers generate output signals, typically containing the longitude and latitude of the particular GPS receiver antenna.
GPS receivers have been employed in vehicle navigation or locating systems. Typically, a conventional GPS receiver is mounted as a mobile unit in a vehicle. Each mobile unit also includes a wireless transmitter which is capable of transmitting the GPS data from a particular mobile unit GPS receiver to a base station via wireless and/or land line communication networks.
The base station will include signal receiving equipment to receive and decode the particular mobile unit ID as well as the reported longitude and latitude of the mobile unit at specific time intervals, such as every few seconds, every minute, etc.
The base station also contains a map database in which maps of a particular geographic region are digitally stored. Landmarks, buildings and other points of interest within the particular geographic region may be also coded with specific latitude and longitude.
It is also known to connect the base station via a communications network, such as the Internet, with a plurality of monitoring units, such as a police dispatcher, ambulance dispatcher, delivery truck dispatcher, etc., to enable the operators of the monitoring units to request location information of the vehicles under their control, such as police cars, ambulances, fire trucks, delivery trucks, busses, etc. The base station, in response to a vehicle location request or on a periodic basis, will transmit a map which contains embedded vehicle location markers to the requesting monitoring unit. The periodic transmission of such data enables the operators to maintain a constant visual awareness, through the monitoring units, of the location of all of the vehicles under their control.
However, considerable data storage is required to store each map having embedded vehicle location markers for transmission to a plurality of monitoring units. This results in relatively large, complex and expensive vehicle locating systems which require a significant investment in terms of time, money and people in order to implement and operate.
Further, the large amount of data required to transmit both map and vehicle location information results in infrequent transmission of the data and, thus, a relatively static vehicle location display. Although the location and movement of a vehicle containing a mobile receiver and transmitter can be monitored by previously devised GPS based vehicle locating systems, only vehicle location is typically available from such systems. Other information which could be of great importance to the central monitoring operator could include the current velocity of the vehicle, a historic record of the path of movement of the vehicle, the velocity of the vehicle throughout such path of movement, etc.
Thus, it would be desirable to provide a vehicle locating system which addresses the deficiencies found in previously devised GPS based vehicle locating systems. It would also be desirable to provide a GPS based vehicle locating system which provides multiple bits of information concerning each monitored vehicle at a low cost in terms of use, system equipment, installation, etc. It would also be desirable to provide a GPS based vehicle locating system which has the ability to separately monitor multiple groups of vehicles from different monitoring stations. It would also be desirable to provide a GPS based vehicle locating system which can make use of readily available GPS receiver and transmitter equipment, monitoring terminal equipment, GPS system improvements, and different wireless and land line networks without significant modification to the vehicle locating system.
The present invention is an automatic mobile object locator apparatus and method capable of locating the geographic position of mobile objects and displaying the geographic position of such objects on a display at a user terminal.
In one aspect of the invention, the mobile object locator apparatus includes a datacenter, a mobile object including a receiver for receiving global positioning system signals from a global positioning system and calculating the position of the mobile object, a transmitter in communication with the mobile object for transmitting the position information of the mobile object to a network, including a wireless communication portion, for receiving the position information from the transmitter and for transmitting the position information to the datacenter. The datacenter stores the position information in a user specific mobile object location database for all mobile objects of one user. Map data for at least one geographic region is stored in a map database. A data network couples the datacenter and user terminal equipment in data communication to enable access to the mobile object location database and the map database by the user terminal equipment to selectively obtain the position information from the mobile object location database and the map data from the map database. The position information and map data are transmitted separately through the data network in response to a user request.
Preferably, the data network is the Internet.
In another aspect of the invention, the position information from the mobile object is stored by the datacenter in the mobile object location database at successive time intervals. The datacenter is capable of accessing the stored position information and calculating and transmitting a data description of a historic path of movement of the mobile object over a predetermined time interval, optionally along with the speed of movement of the mobile object at selected locations along such path of movement.
In another aspect of the invention, a method of automatically locating a mobile object comprises the steps of:
mounting a receiver on a mobile object for receiving global positioning system signals from a global positioning system;
calculating the position of the mobile object from the global positioning system signals;
providing a wireless transmitter in data communication with the receiver for transmitting the position information of the mobile object;
communicating the position information to a datacenter;
storing the position information in a user specific mobile object location database;
storing map data of at least one geographic area in a map database;
providing data communication between the datacenter and at least one remote user terminal;
providing the user terminal with a selection of one of the map data and the position information and transmitting the user terminal selection to the datacenter; and
transmitting the selected one of the map data and the position information from the datacenter to the user terminal.
The mobile object locator apparatus and method of the present invention provide significant advantages and improvements over previously devised vehicle locating systems. By storing position information from each vehicle containing a mobile object in a specific customer database for all like vehicles associated with a particular customer, the mobile object locator apparatus of the present invention is capable of monitoring different groups of vehicles and maintaining the position information for such vehicles separate from position information for other customer""s vehicles.
The mobile object locator apparatus and method of the present invention, by transmitting map data and mobile object position information separately from the central station to the user terminal equipment, provides more efficient data communication with the user terminal equipment since updated mobile object position information or different maps may be transmitted independent of each other through the data communication network to the user terminal equipment.
The storage of the mobile object position information at time intervals in a database also enables the present apparatus and method to provide a history of a particular vehicle""s path of movement and speed.